Mechanism for forming tubular rivets



Oct. 9, u1945. y EQF. HESSELMAN i MECHANISM FOR FORMING TUBULAR RIVETS INVENTOR 3537 evwARoYFR/wzumnmv ATTORN EY l l 'EL F. HEssELMAN MECANISM FOR FRMING' TUBULAR RIVETS ocx. 9, 1945.

5 Sheets-Sheet 2 Filed oct. 26, 1943 INVENTOYR l EDWARD-FRANZ- HEELMAN fllll.

ATTORN EY INVENTOR 5 sheets-sheet 4 f Oct. 9, 1945.

Patented Oct. 9, 179745 FoRMiNo TU'BtiL-nn -Y mms Y j. Asniqstipn-octossr 2 6, ies-s,4 serial No. 5071700 s j L lnAustrala October 27,1342,

tliose Vdese'riiloecl and illnstratedin the .complete speciiicationof BritishlatentNo. 4 9Q,017 ,fd 9 d. Jenneryalslnr i Y Meehnisinl aoeordine tj this. inventionis. one plioeible to, on loenartlvY constituted by, a oomrnon pinehine-Diessottne kind having astatioilanffWolili-titille,l and v a slide, ram, or head which is recienoentalol-e A in a dineetion; et right ensleslto the -snnfaee ofthe table'. l

The meen isin snloiest lieneot mainly oom.- pt-ises oneorinore mele nnneheslixed on a retin- .V nro stable p11,,n eliiiisfine sslieslrnaiY female'r die. eissembly mounted, onagpresns Workta le of anotateble-platen and a. nluitalitv. 0. elements in said platen, antiV means. responsive to reciprocating movements. of. seid .head for ,intermittently part-.rotating the; platense. vtlilat said female die e1enier1tsy are, conse@ntiveliiF registered Witnftne mele pnnohoir n iintliesl l f Air-example' of. the. invention is illustrated in tneaooomnanyine drdwines.

Eig.. 1 is. a planer a.. f e.. als Y,die assembly tne reeipmestable; head or 'punch assembly beine;

omitted-l. The positions, oi the Seremiparts, in this vieni ate those Willen eorrespond, Withz the regiprqeataeie; liefiolv being. almostat the enel of. itslde-Wnror W.o r-k ir 1g s tnollse-r i Fia. 2 .is et seotional 'eleration -inelnolina the s Glaims. (c1. r11i- 13) -Y Eig. 7 is, a, sectional elevation takenon. the

Planes indicated by line. l-l in Fie-l '6= Ei a s eetional-V'detail view which 11e--V heatsa portion of 7 with the parts'- posiitiene@ correspondence with the punch-head beinefully deseended.

scale for clearijuess.

Fi g 9; repeats a. portion of Figj biitvwith the parte'p ositionec l as they are just priort arrival inthe positionsshowninliis 8 1i'i g. 10 repeats a portion of; Fier 8' onf s leisen eige. iiapqpiz are detail 'pian- 'a'pdlf-ro'pt ele'- vation respectively of'Y a rivet holding devicefornnne pertof the indohine.'

l Fig 13 repeatsrfig. 12- but with the 'partsfposintionedasdthevv are i.iistfafter 'leaving the positions i4' ipa plan Aof a-iollowdie illustrated in am c iajaion with the machine platen inflligs." 1

Fig# 15 is a sectional'elevatin takenon the plexivinlieated` by 1ine` I-5 -`|5- in Fig? 14. 'I 'lie` `loiincli assembly is, incliideldf and isshown fullydesoended. Y

.Figsp '16' to 2l) shovvithe progiessive-ehang'esiri punohi dsseinhlm and teken on the plane indioated, ha line .'2 -:Z..- Fig l. this ViewYV rthe nunon. assembly is the upper limit oiits itinere-r inentrsnee l i e vI iig'. a isY ejseetionelelevetion taken, the planes indicated-lov line tra in Eig- 1 the nniflttlli assembly is shown, at the lower limit of. its, movementralle.,

l is steen elevation inertia sectioned?, .taken on. theffnlsnesindioated by line ll-Lin Eig,

In. this 1, Witldthepunell .assembly f nllv` descended as Eig- 5 .is an incomplete sectional plan: teken on line 5:5;in Eis. 4, f

#Elia 6 is any liloomplete plein.y of, the female die essenblst and parts related thereto. 'I lie Rosie@ the formationoff rivet blanks from stripstockby the follow-dire shovvn in Figs. 14 'and-15;

Fig` 2r1 illustrates afiivet blank prodiicecl by theiollowfdie.

Eigl 22 isla detail view illu'strating a stepin the fprinatiori oa rivet; in and'by a female die anclby a forming punch.

l Eig; 23 is asimilarvievv in Iiig.Y 22, showing a borje-trueing lpunlor drift engaging a partly iorined rivet in a female die'. Eig. 24 is, a section offaiinish'ed rivet'. Figs, 1 to 8 are drawn to the sainescale, Figs. 9,'to. 2 3 aredrawnona'somewhet larger seele for clearnessg'dnd Eig,- 2 fi is drawn on a. still larger s,o al e,.-

The. platen 2 5. is -freely rotatable about, a4 centrafl 'hearina 2 6; on a pedestal ZlQXed to abase block 28;. The bloekez is adapted for ai'xture (for example by wings 2 9= and boltsr 30). on the work-table 3, I; ofV acommori punching, press. The platen'has 'al concentric groove 32 in its. underface, whereby itseats on a bolster ringf3f3. The platen is rotarilysldable on the ring 33,' the-latterbeing` fixed on the base block- 2 8 inconcentricity with the ,bearing 26; The platen has-its peripheraledge divided into-two parts bya iiange 3,4. yAbove ange the platen peripheryf'is and locating notches 36. The notches 35 and 36 are referred to later herein.

A plurality of female die elements 31 are inset and xed in the platen with their top faces flush with that of said platen. Each of these die elements has a central rivet-forming cavity 38 therein, and the axial depth of the elements and,

the cavities therein is such that the top face of the bolster ring 33 constitutes a iioor for said. cavities. The cavities 38 are equally spaced about a pitch circle (3S-Fig. 1) whereof the centre is coincident with the rotational axis of the'platen. The platen is preferably furnished with a plurality of register holes 40 which are equal in number to the female die elements, and like the cavities 38, are arranged as an equally spaced-series on a pitch circle whereof the centre is coincident with the rotational axis of the platen.

A punch-head 4IA has one or more rivet-forming male punches such as 42 and 43 xed thereon. The head 4I is reciprocatable, by` means of known drive devices, in a direction normal to the plane of the pitch circle 39 (that is, normal to the platen top surface). The range of movement of said head is such that when the head is at the bottom of its stroke, the punch 42 (for example) enters one of the female die elements registered therewith, to the extent illustrated by Fig. 22; and when the head is at the top of its stroke ya rivet knock-out or lifting rodV 44 (Fig. 7) which is fixed relative to said head, enters one of the female die elements, upwardly and from the bottom thereof, to the extent shown in Figs. 'I and 13.

A rivet is formed from a washer-like blank 45 (Fig. 21) within one or other of the female die elements, by the engagement therein of the punches 42 `and l113, during each complete stroke cycle of the head 4I. The platen is (of course) held stationary with two of its female die elementsin axial alignment with the punches 42 and 43, while said punches-are at or near the bottom end of their stroke. While said punches are performing the remainder of their stroke cycle, the platen is intermittently part-rotated in order to bring the Ifemale die elements consecutively into register with said punches.

The means for intermittently part-rotating the platen are actuated in response'to the reciprocatory movements of the punch-head. 'Ihese means comprise the mentioned ratchet notches 35 and a pawl-lever 46 fulcrumed at 41 on a ringbracket 48 and loaded to bear against the platen periphery by spring 49. Av leaf spring 5D xed at 5I .and held in position by' stubs 52, may be provided to impose additional resilient loading on the pawl .46 when it is at or near the end of its work-strokeas shown by chain dotted lines (53) in Fig, 1. The ring-bracket 48 is fixed on' a collar 54 which isfreely rotatable (but is restrained against axial movement) within a ring bearing 55 'fixed ontthe base block 28. The collar 54 has a radial hole 56 therein which houses a pin 51. A freely rotatable follower roller 58 is mounted on the inner end of pin 51. This roller Arides in a cam-groove formed in a post 5'9 which'is fixed on the head4l and which is freely movable endwise within the bracket 48, the collar 54, and a hole in the base block 28. The mentioned camgroove consists of upright straight end-portions 60 and 6| and an inclined or helical central portion 62'. The arrangement is such that during the -rst (approximately) one-third portion of thev punch-head upstroke, the roller 58 rides in the cam-groove portion 6I, and the pawl 46 is thus not moved from the position shown by full lines in Fig. 1; during the second (approximately) one-third portion of the upstroke, the roller 58 rides in the cam-groove portion 62, yand the pawl 46 is thereby moved to the position shown chaindotted in Fig. 1, thus performing its working stroke in turning the platen through the required part-rotation thereof; and during the third and final (approximately) one-third portion of the upstroke the roller 58 rides in the cam-groove portion 60, and the pawl is thus held in the position shown chain-dotted in Fig. 1. During the middle portion of the punch-head down-stroke, the pawl is restored to the full-line position (Fig. 1) in readiness for its next working stroke. It will be noted from the foregoing that part-rotations of the platen are eiected and completed during the period that the punch-head is moving through a one-third (approximately) central span of its upstroke, and consequently that the platen is stationary during about flve-sixths of the stroke cycle of the punch-head. During these halting periods all the working operations on a rivet blank or on a formed rivet are effected. In order to avoid back-lash inaccuracies due to the follower roller 58 being necessarily a running iit within the cam-groove 6|l-6|-62, the bracket 48 is loaded by a tension spring 63 which is anchored at 64 to the bearing 55, .and at 65 to the bracket 48. This spring 63 rides in a peripheral groove 66 inbracket 48 and its effectis to oppose performance of the working stroke of the bracket 48 thereby ensuring that during said working stroke the roller 58 rides hard against the driving side of the cam groove portion 62.

VThe ratchet pawl and cam devices just described are designed to turn the platen precisely through the correct angle required for the consecutive advances of the female die elements. Means are provided, however, to ensure that the platen is halted in correct position, and is so held until it is due for a next move. Y

The platen halting and holding means comprise the mentioned halting and locating notches 36 and a chisel-ended plunger 61 which is adapted neatly to home in said notches. 61 is axially movable within a housing 68 fixed on the lbase-block 28, and at all times is influenced to move towards the platen centre by compres- :sion spring 69. The loading of spring v69 and the angularity of the notches 36 are such as t0 ensure firm engagement of the plunger in the notches, without preventing the plunger from being displaced from the notches when the platen is part-rotated under compulsion of the pawl 46.

Thev loaded plunger 61 and the notches 36 may be wholly relied on for halting and holding the platen with its female dies in positions of true register with the punches such as 42 and 43. For preference however, additional registering means are provided by way of precaution. In the illustrated arrangement of the invention such additionalmeans are provided, and they comprise the mentioned holes 40 and a registering plunger 1D. This plunger 10 is neatly slidable within any one of the holes 40 and in a hole 1I (see mainly Fig. 3) in the base-block 28. Plunger 10 is xed on a bracket 12 which in turn is xed on the bottom end of a push-rod 13. This rod 13 is slidable in a bore 14 partly formed within the pedestal 21 and partly in a sleeve 15 xed in the baseblock 28. The push-rod 13 has an upwardly extending stem 16 whereby it is fixed to the punchhead 4I. The stem 16 is preferably threaded (as indicated at 11) for engagement within a nut 18, having a flange 19, and for reception of a The plunger meeneem loclnut 811.E The nutilmissecuredstoitheepunchi. head by a. clamping: plateV 8 l; and; screws 02;r On., r'elaafzation` of' screws.` 825 (and lock-nut.. 809;? the: nutiltmaysbeturnedto vadjust-,fthe effective-length; ofthef-stemi'l', The' correct adjustnr1-entloff` the.: stem' 18, and" the. length'- ofplunger. 10;. are; such; that` the plunger-ris Well; clear.- of'- any holecsuch: asi-"4W whenever thel platen'. is moving. .1m each; strokel cycle= of the mechanism, thenlunger .fenters'one-of the hol'esAD shortly.:aftenthefplatenf has" been@A part-rotated: andV shortlyr before the:

Y preferably moreacutely angled than are; ther 'not'cl'ie's` 35v (as` shown) 'This enablessaidgend.. tojscrape-thef notch interiors and thus.more..:posip tively remover', unwanted? matters: therefrom. A; similarf device to tiiatrnumbered 83:-.85-85 may. be provided for cleaning the notches `l-iandz.may; be installed onthat part; ofthef base-block'shownv the-ri'g-lit-hand bottom corner of Fig.Y 1. Rivets are formedl inthe female die elements 31'; by.punches suchv as 42iand43; out offwasll'er likev` blanks such; as 45 (Figi, 2.1). pre-emplaced inl said dieelementsf atqa selectedtblank-receiving: station. The: blank-receiving. station.. may.' Coin'.- cide W-ithi any one otthe: halt-ing positions-.o the elements 31; provideditgis: one of those. positions- Which is circumferentially ahead-ot or the `same as that position in which theriirst rivet forming operation occurs; and-provided'it is one oi-thos:

, positions in which.y theV die' element,y in;l thea ordi?.

nary courseofl operation, isempty` orfhas; been emptied'.- Inl the illustrated embodimenteof the inventionA the blankereceiyingstation corresponds; with thel right-mosti" or@ three-oolo.c1':? tenialo. die4 halting positionY in.y Fig. 1i Successive. eine placement of-thevblanksiinthe female diesL consecutively halting at the receiving. station, may be-feffeotedVv manually or as the end' operation; or afollow die (describedlzlater. herein) or otherwise. The pla-ten 2.5 turns" anti-elo cltvvise; andi; a Y. blanls leaving the receiving StationfinJ one of;E the elements; 31. arrives inl ay punching stationv (one oclock pos-itionin Fig. l.) Where.- it. is. acted uponjasshown iniFig. 22by. thegpunch 42;. The partly formed rivet leaving the punchingstation arrives in a bore-trueing station. (twelve oclock position inFig; 1') Where it is acted upon bythe drift 43: The-finished. rivet (851, Fig;.2,4) requires to belifted out. of the. dieinwhioh. it was for-med, prior to-the receipt, by thzat.die,..ofa fresh blankV at the blank-receiving station.. In Fig. 1 the ten oclock die position. is the rivet-y lifting station.

Finished rivets maybelifted out offthe: female diefelements in any` one of several Ways (they may even be hooked out manually); for prefj- F erence,V however, they areylifted clear. of; thenarticulardie (31) by the'l-ifting rod; 44. This rod 44 is slidable in a hole` in. the.' bolster rino: 33a This hole is so' positioned thaeieregisterswith the bottomV of the cavity' 381`oi'any: one. ofi the. female dies ampia-ced in ,the rivet unina-station.

The; rodfldrhase a; pilot; stem; ii-l-t (Eis.Vv 1-2) ,l which. isztablerfllelystzrentl' thelbore ofarivet.. Therod xegdy uponia-plunger' 018l freely slidable;v as.1e.` -2?/ebearing?` 09; inthe base blocleV 2,8. The plungerf 8,;8 .is-,= xedf on bracket 1.2: asV4 indicated atifllk. l Y

By easonfofi rodaabeingf fixed relative .y to theI puno fhead; it;` follows; that; during; normal, op4 Grammy.. a .finsheghrivet' is lifted out of, ak female cneyat:v the-,lifting station.. ever-y time the` punobel headiapproaches the top end of'itsfupstroke. Therivets so;-,lif;te.d;l 'may be; picked; offthe ,rod` 41|.l manuallnr or otherwise..- For preference` rivet transfer mechanism; asgfollovvsy isemployed. Y

'Ilie'fpnnchshead-- has-. a. post: 9| fixed thereon. This'. ost-isgclosely similar to'that nllmbered 59- andfis isiinilarlyrslidable withrra ringfbr-acket 9?.,v a. collartofwhich1thezbrackot;SZfisxed, yandv hushr 95:. (Fig: 4).' a. hole; in. the.l basefbloclr.` 28:.- The bracket-:ande Collarr assemblyI StZ-413t is; freely;`A rotatable;- about; the posti 9L andfzis, re strainediagainst axialjzmovementf byvaf ringybeara ing: 95; The; collar 913 carriesY a; radial pin 95% for.` at freely revolubleffollovver-- roller 931,* which .rides Within; a 'oarnegroove in; thefpost 95|... This groove'consists oftastraight b'ottom-portion 98; a central inclined. or; helicali portiony 992.- and a`- aredzpcrtion #003. vThering-bracliet 92 is-pro vided: vvitl'iaj tension` spring |01.- to,restrain,back-r lash.VY movementsl thereoffs. The; spring |.0.-|-- rides:V

in@ a .peripheralf groove.: Hita; is:y anchored; to the..

bracket 92 at.'v HIB?, and-. to the;` ring-bearing 95 at: |002.: y

The bracket., 92.- has.: anfintegral or aiiixed` arm |05 thereon. A pair; of: rivetgripping leversf- |06. are fulcrum-ed: onjthe. arm|015 at |0'|f (Figi, lil). Pegs` imi;` on. the levers,` andpegs I 09; on. the arm.

- |05, areconnected-by,tensionsprings H0. Thesesprings.. inlluence vmutualv approach of; the rivets.

vents'toofy closerv approach' ofsaid' jaws.; These jaws have; roundedY or.Y cutaway undersidesl as showin. at H31 W'hen thepunchf-head;I is iin aplorximately.v the top one third part of its movement range, the follower roller. 9.1.-' is. Within. the groove; portion 98, andi, henoethe arm |05; is, in.` the position` shown?. in.-k Figs... 6 and: 7;; that is; vvi-ththejaws ||i| lying-directly; above therivetlfting; station. Wl'ienjthe.- punch-head is-,lnearly at. the topv of. its upstroke, therodzdllcommences to lift arivetat the` lifting station (Fie: 12') and. then thrusts it between the-rounded.: jaws Ishii int-o1 thev position shown: in'PigS. 7..; and; 1:3.. As the punch-.head

f commences descent, the rodi 414 leaves-the rivet,

which: remainsfheld by thejaws |f||.. Shortly after; therollen 91; entersthe: cam-groove; por.- tionA '99, andf the arm |'05fis thereby swung; into thev positionsh'own: in: Fig. 1. the transferreds riyet; is poised directlyfabove a small pedestal lilAc xedl on the;A base-block` 28|. Pedestal; IA; (see Vmainly Figs; '7v to- 10); has a bore bl-linto which. the body ofa.rivetmay freelyenter.- Dur-ing continu'eddescent ofthe punchhead2' the bore'- ofthefrivet,` over' pedestal Hlly is entere'dfby; aipilotr stem: |:|.0; (see Fig...9). Mean- While, the? follower roller.. 912 (due: to. the influsence1 of spring. Iijoiridesagainst theupright side Hlt of.r the; cam-groove portion; |00 andgtherefore, for the time being, thesrtvett is held station-ary above the pedestal |24:

Thepilot stem. H6 extends from a shoulder H8? on the body of-y a pinr Il -9f which is slidable in -a sleeve' |20, ixed` tothefpunch-head M. The diameter; ot thebore of sleeye |.Z0is.such thata In,k this position said bore (as shown in Fig. 9) the arm |05 is contacted by the work edge |26 of a cam plate |21 fixed to the punch-head. Continued descent of the punch-head, c-auses the cam |21 to displace the arm |05 sidewardly so that the jaws relinquish their grasp on the rivet in opposition to the loading of springs ||0. During the sideward displacement of arm |05, the punch-head `has continued to descend, although the rivet has been prevented from descending while still engaged by jaws |08'. This causes a moment-ary halting of the pin H9, which is allowed'for, by the ability of the head |28 of pin ||9 to rise within the cavity |29 (Fig. 9) thus raising the push-rod 2| against the loading effect of ball |23 and spring |24. As soon as the jaws |06 are clear of the rivet it is emplaced in the top of pedestal I4, yas shown in Figs,` 8 and 10, with the lower end of sleeve |20 rmly engaged about the rivet head. (At this point it may be noted that during the sideward displacement of the arm |05, the roller 91 is in the flared portion |00 of the cam-groove. The width of the portion enables the said sideward displacement and the spring |0| yieldingly opposes it.)

The position of the sleeve |20, shown in Figs. 8 and 10, corresponds with the bottom end of the punch-head downstroke. From this point, the sleeve |20 commences to rise with the rivet firmly gripped therein by its head. In addition to lifting the rivet from the pedestal, the sleeve |20 also functions as a shear whereby ragged edges or burrs on the periphery of the rivet head are sheared off as the sleeve engages the rivet head as shown in Fig. l0.

As the punch-head rises, the roller 91 engages in the groove portion 99, and the arm is again swung over the platen in readiness for reception of a next rivet at the lifting station. As the punch-head nears the top of its upstroke, the push-rod |2|` is depressed by the abutment |25 so that these parts assume the positions shown in Fig. '7, and the rivet being disengaged from the sleeve |20 freely falls from the pilot stem of pin ||9. The falling rivet may be directed as desired, by an air blast, in known manner. An air blast nozzle is indicated at |30 (Fig. 7).

The use of the sleeve |20 as a rivet-head trimming shear, results in small shavings and ragged burr pieces being shed about the `vicinity of the pedestal ||4. It is the tendency of these small Waste pieces to lodge on the platen flange 34 which largely establishes need for a notch-cleaning chisel such as 83. Most of the small waste pieces are cleared from the vicinity of pedestal ||4 by partly surrounding that integer with an upstanding Wall |3|, and by the provision of an air nozzle |32 (Fig. 1) the blast of which sweeps round the interior of wall |3| and clears un-4 wanted matters therefrom.

As previously noted herein, washer-like rivet blanks such as 45 (Fig. 2l) may be fed into the female die cavities 38 arriving and halting at a .selected blank-receivingstation, in any one of several different ways. For example, the blanks may be manually emplaced' in the.: dies, or vthey may be arranged as an upright column within a tubular feeding magazine, the open bottom end of which is located directly above the receiving station. Again, the blanks may slide towards and into the receiving station by way of a chute or the like.l It will also be appreciated that blanks such as 45 may be marde in many different ways.

In the illustrated embodimentof the invention, the required blanks are made in a follow-die,

' from strip stock; and said die is combined with the mechanism already described herein, in such manner that the rate lof blank production by said follow-die is exactly equal to the required rate of blank intake by the female die elements 31, and a portion of the follow die assembly is instrumental in emplacing the blanks in female die elements halted at the receiving station.

Referring mainly to Figs. 14 and 15, the followdie comprises a main-plate |33 having a groove in its upper face. This groove consists of a wide portion |34 and a narrow' portion |35 as shown in Fig. 14. The main-plate |33 is fixed on a block |33 which in turn is fixed on the baseblock 28. The arrangement is such that the groove is directed towards the axis of the platen, and (in plan) the longitudinal centre rline of the groove portion |35 radially intersects the pitch circle 39 at the blank receiving station as will be apparent from Fig. 1. The groovel |34|35 together with a roof-plate |31 constitutes an infeed channel for strip stock |38. While in this channel, the stock is acted upon by a chiselpunch |39, a drill-punch |40, a blanking-punch |4|, and a shear-punch |42. These four punches are fixed on the punch-head 4|, respectively in register with the die-holes |43, |44, |45 and |46. The axis of die-hole |45 coincides with the axis of any Ione of the female dies 31 which happens to be at the receiving station. The die-hole |40 has an air-blast pipe |41 open to one end thereof, and a scrap departure-chute |48 (see Fig. 1) open to the other end thereof.

In operation, a stock strip |38 is inserted into the follow die in the direction indicated by arrow in Fig. 14. The width of the stock is greater than that Yof the groove portion |35 and consequentlythe side |49 of hole |43 halts the strip |38. Descent of the punch-head causes the punch |39 to remove an edge portion from the strip as indicated at |50 (Fig. 17). The narrowed por- -tion of the stock is able to enter the groove portion |35, consequently provided endwise pressure in the direction'of the arrow in Fig. 14, is maintained, the strip intermittently feeds into the follow-die, by an amount equal to the length of hole |43, on each occasion that the punch |39 recedes from said hole. The narrowed strip is then holed by punch |40 as indicated at |5| (Fig. 18). When the holed strip arrives below punch |4|, the pilot |52 of this punch loosely engages within the hole due t0 punch |43. The punch proper (I4 l) then cuts a Washer-like blank 45 (Fig. 21) from the strip, leaving a hole |53 (Fig, 19) therein. As the waste end portion |54 (Fig. 20) arrives in 'the hole |45 it is sheared off by punch |42 and is blown clear of the die by air blast from pipe |41 and by Way of chute The length of punch |4| is such that after` it has cut a Washer-like blank, it thrusts it right through the main-plate |33 andemplaces it in the female die cavity 38, in the blank-receiving station, as shown in Fig. 15. As the platen rotates, the rivet is formed as shown in Figs. 22 and 23, and is subsequently lifted out of theA platen dies by rod 44. The rivet is removed from rod 44 as previously described herein.

In the mechanism described herein, the platen has twelve female die elements and two rivetforming punches. It will be readily appreciated that there may be more or less than twelve female-die elements provided the number is at least equal to the number of separate rivet-forming operations to be performed; also, that there may be only one rivet-forming punch or more than two` thereof depending on the shape complexity or other characteristicof the rivet to be made. 'In this connection it may be' noted that the machine subject hereof is useable in the manufacture of small objects .which may bear some similarity of form to the rivet shown in Fig. 24 but are not necessarily rivets within the ordinary meaning of that term. In short, the invention subject hereof is called rivet-forming f mechanism because it has been devised and designed primarily for that purpose, but its utilities are not necessarily confined to carrying that purpose into eiect.

I claim:

1. In a machine for forming tubular rivets and the like and having a rotatable plate carrying a plurality of female die elements and a head adapted to be reciprocated perpendicularly to the plane of rotation of the plate and carrying a male punch, a mechanism actuated by said head to produce step-wise rotation of said plate comprising a support fixed to'said head and provided With a cam groove, a ring-bracket slidably mounted on said post and restrained from axial movement, a member secured to said ring-bracket and extending into said cam groove, and a pawl member having one'end rotatably secured to said `ring-bracket and its other end adapted to selecadapted to be reciprocated perpendicularly to the plane of rotation of the plate and carrying a male punch, a mechanism for transfering the rivets from said die elements comprising a support fixed to said head and provided with a cam groove, a ring-bracket slidably mounted on said post and restrained from axial movement, a member'secured to said'ring-bracket and extending into said cam groove, an arm having one end fixedly secured to said .ring-bracket, a pair of levers pivotedly secured to the other end of said arm and adapted to engage the rivets and resilient means acting on said levers.

3. In a. machine for forming tubular rivets and the like and having a rotatable plate carrying a plurality of female die elements and a head adapted to be reciprocated perpendicularly to the plane of rotation of the plate, a. mechanism for transferring the finished rivets from said die elements comprising a support fixed to said head and provided with a cam groove, a ring-bracket slidably mounted on said post and restrained against axial movement, a member secured to said ring-bracket and extending into said groove, an arm having one end xedly secured to said ring-bracket, a pair of levers pivotedly secured to the other end of said arm and, adapted toengage a rivet, and means for removing the rivets fromkbetween said arms, said means comprising a stationary' member provided with a bore adapted to receive a rivet, a sleeve fixed to said head and provided with a bore in axial alignment with the bore in said member and aadpted to tightly embrace a rivet, a pin slidably mounted Within the bore of said sleeve and movable between a lower position and an upper position, a pilot stem on the lower end of said pin and adapted to enter the bore of a rivet, resilient means including a push-rod to retain said pin in its lower position, and a stationary stop engaging said push-rod when the head is nearthe end of its movement from the plate.

EDWARD FRANS HEssELMAN. 

